Business Overview and Significant Accounting Policies	3 Months Ended
Apr. 01, 2018
Accounting Policies [Abstract]
Business Overview and Significant Accounting Policies	Business Overview and Significant Accounting Policies Unless we state otherwise or the context otherwise requires, references to "Masonite," "we," "our," "us" and the "Company" in these notes to the condensed consolidated financial statements refer to Masonite International Corporation and its subsidiaries. Description of Business Masonite International Corporation is one of the largest manufacturers of doors in the world, with significant market share in both interior and exterior door products. Masonite operates 65 manufacturing locations in 8 countries and sells doors to customers throughout the world, including the United States, Canada and the United Kingdom. Basis of Presentation We prepare these unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the United States of America ("GAAP") and applicable rules and regulations of the U.S. Securities and Exchange Commission ("SEC") regarding interim financial reporting. Accordingly, they do not include all of the information and notes required by GAAP for annual financial statements. In the opinion of management, all adjustments consisting of normal and recurring entries considered necessary for a fair presentation of the results for the interim periods presented have been included. All significant intercompany balances and transactions have been eliminated. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect reported amounts in the financial statements and accompanying notes. These estimates are based on information available as of the date of the unaudited condensed consolidated financial statements; therefore, actual results could differ from those estimates. Interim results are not necessarily indicative of the results for a full year. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017, as filed with the SEC. Our fiscal year is the 52- or 53-week period ending on the Sunday closest to December 31. In a 52-week year, each fiscal quarter consists of 13 weeks. For ease of disclosure, the 13-week periods are referred to as three-month periods. Certain prior year amounts have been reclassified to conform to the current basis of presentation, related to Accounting Standards Updates ("ASU") 2017-07 and 2016-18, as described below. Changes in Accounting Standards and Policies There have been no changes in the significant accounting policies from those that were disclosed in the fiscal year 2017 audited consolidated financial statements, other than as noted below. Adoption of Recent Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued ASU 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” which amended Accounting Standards Codification ("ASC") 715, “Retirement Benefits”. This ASU required disaggregation of the service cost component from the other components of net benefit cost. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. This standard was effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years; early adoption was permitted and retrospective application was required. We have utilized the practical expedient allowing the use of the prior years' disclosed service cost and other cost as the basis for our retrospective changes in presentation. The adoption of this standard changed the presentation of the other components of net benefit cost in our condensed consolidated statements of comprehensive income (loss), requiring the reclassification of a $0.3 million benefit related to other components of net benefit cost out of previously-presented selling, general and administration expense and into previously presented other expense (income), net, for the three months ended April 2, 2017. The effect of this reclassification reduced previously-presented operating income by this amount for the same period. The total benefit which will be reclassified for the years ended December 31, 2017, and January 1, 2017, will be $1.1 million and $0.5 million, respectively. In November 2016, the FASB issued ASU 2016-18, "Restricted Cash Flows", which amended ASC 230 "Statement of Cash Flows". This ASU clarified how entities should present restricted cash and restricted cash equivalents in the statement of cash flows. The new guidance requires entities to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, entities no longer present transfers between cash and cash equivalents and restricted cash and restricted cash equivalents in the statement of cash flows. This ASU was effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods; early adoption was permitted and retrospective application was required. The adoption of this standard changed the presentation of restricted cash in our condensed consolidated statements of cash flows, which is now being combined with cash and cash equivalents, and had the effect of an immaterial decrease to previously-presented cash flow used in investing activities for the three months ended April 2, 2017. In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers," which created ASC 606, "Revenue from Contracts with Customers," and largely superseded the existing guidance of ASC 605, "Revenue Recognition." This standard outlined a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and superseded most current revenue recognition guidance, including industry-specific guidance. The core principle of the revenue model is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB issued ASU 2015-14, "Revenue from Contracts with Customers - Deferral of the Effective Date," and the guidance would now be effective for annual and interim periods beginning on or after December 15, 2017. We have adopted the guidance of ASC 606 as of January 1, 2018, using the modified retrospective method and have applied the standard to only those contracts which were not completed as of the transition date. The adoption of this standard did not have any material impact on revenues in the three months ended April 1, 2018. Prior period amounts were not adjusted and have continued to be reported in accordance with our historic accounting under Topic 605. While we considered an adjustment to opening retained earnings as prescribed by the modified retrospective method, there was no material adjustment ultimately required. Furthermore, there was no material difference between the prior period amounts as reported under ASC 605 and such amounts as would have been reported under ASC 606. Information about the nature, amount and timing of our revenues from contracts with customers is disclosed in Note 10. Revenues. Our accounting policy for revenue recognition is set forth below. Revenue Recognition Revenue from the sale of products is recognized when control of the promised goods is transferred to our customers based on the agreed-upon shipping terms, in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. Volume rebates, expected returns, discounts and other incentives to customers are considered variable consideration and we estimate these amounts based on the expected amount to be provided to customers and reduce the revenues we recognize accordingly. Sales taxes and value added taxes assessed by governmental entities are excluded from the measurement of consideration expected to be received. Shipping and handling costs incurred after a customer has taken possession of our goods are treated as a fulfillment cost and are not considered a separate performance obligation. Shipping and other transportation costs charged to customers are recorded in both revenues and cost of goods sold in the condensed consolidated statements of comprehensive income (loss). Other Recent Accounting Pronouncements not yet Adopted In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)", which will replace the existing guidance in ASC 840, "Leases." The updated standard aims to increase transparency and comparability among organizations by requiring lessees to recognize lease assets and lease liabilities on the balance sheet and requiring disclosure of key information about leasing arrangements. This ASU is effective for annual periods beginning after December 15, 2018, and interim periods within those annual periods; early adoption is permitted and modified retrospective application is required. While we are currently assessing the impact that ASU 2016-02 will have on our consolidated financial statements, we anticipate that the primary impact upon adoption will be to our consolidated balance sheets from the recognition, on a discounted basis, of our minimum commitments under non-cancelable operating leases, resulting in the recognition of right to use assets and lease obligations. Our current minimum undiscounted lease commitments under non-cancelable operating leases are disclosed in Note 9. Commitments and Contingencies.

Business Overview and Significant Accounting Policies

Unless we state otherwise or the context otherwise requires, references to "Masonite," "we," "our," "us" and the "Company" in these notes to the condensed consolidated financial statements refer to Masonite International Corporation and its subsidiaries.

Description of Business

Masonite International Corporation is one of the largest manufacturers of doors in the world, with significant market share in both interior and exterior door products. Masonite operates 65 manufacturing locations in 8 countries and sells doors to customers throughout the world, including the United States, Canada and the United Kingdom.

Basis of Presentation

We prepare these unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the United States of America ("GAAP") and applicable rules and regulations of the U.S. Securities and Exchange Commission ("SEC") regarding interim financial reporting. Accordingly, they do not include all of the information and notes required by GAAP for annual financial statements. In the opinion of management, all adjustments consisting of normal and recurring entries considered necessary for a fair presentation of the results for the interim periods presented have been included. All significant intercompany balances and transactions have been eliminated. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect reported amounts in the financial statements and accompanying notes. These estimates are based on information available as of the date of the unaudited condensed consolidated financial statements; therefore, actual results could differ from those estimates. Interim results are not necessarily indicative of the results for a full year.

These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017, as filed with the SEC. Our fiscal year is the 52- or 53-week period ending on the Sunday closest to December 31. In a 52-week year, each fiscal quarter consists of 13 weeks. For ease of disclosure, the 13-week periods are referred to as three-month periods. Certain prior year amounts have been reclassified to conform to the current basis of presentation, related to Accounting Standards Updates ("ASU") 2017-07 and 2016-18, as described below.

Changes in Accounting Standards and Policies

There have been no changes in the significant accounting policies from those that were disclosed in the fiscal year 2017 audited consolidated financial statements, other than as noted below.

Adoption of Recent Accounting Pronouncements

In March 2017, the Financial Accounting Standards Board ("FASB") issued ASU 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” which amended Accounting Standards Codification ("ASC") 715, “Retirement Benefits”. This ASU required disaggregation of the service cost component from the other components of net benefit cost. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. This standard was effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years; early adoption was permitted and retrospective application was required. We have utilized the practical expedient allowing the use of the prior years' disclosed service cost and other cost as the basis for our retrospective changes in presentation. The adoption of this standard changed the presentation of the other components of net benefit cost in our condensed consolidated statements of comprehensive income (loss), requiring the reclassification of a $0.3 million benefit related to other components of net benefit cost out of previously-presented selling, general and administration expense and into previously presented other expense (income), net, for the three months ended April 2, 2017. The effect of this reclassification reduced previously-presented operating income by this amount for the same period. The total benefit which will be reclassified for the years ended December 31, 2017, and January 1, 2017, will be $1.1 million and $0.5 million, respectively.

In November 2016, the FASB issued ASU 2016-18, "Restricted Cash Flows", which amended ASC 230 "Statement of Cash Flows". This ASU clarified how entities should present restricted cash and restricted cash equivalents in the statement of cash flows. The new guidance requires entities to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, entities no longer present transfers between cash and cash equivalents and restricted cash and restricted cash equivalents in the statement of cash flows. This ASU was effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods; early adoption was permitted and retrospective application was required. The adoption of this standard changed the presentation of restricted cash in our condensed consolidated statements of cash flows, which is now being combined with cash and cash equivalents, and had the effect of an immaterial decrease to previously-presented cash flow used in investing activities for the three months ended April 2, 2017.

In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers," which created ASC 606, "Revenue from Contracts with Customers," and largely superseded the existing guidance of ASC 605, "Revenue Recognition." This standard outlined a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and superseded most current revenue recognition guidance, including industry-specific guidance. The core principle of the revenue model is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB issued ASU 2015-14, "Revenue from Contracts with Customers - Deferral of the Effective Date," and the guidance would now be effective for annual and interim periods beginning on or after December 15, 2017. We have adopted the guidance of ASC 606 as of January 1, 2018, using the modified retrospective method and have applied the standard to only those contracts which were not completed as of the transition date. The adoption of this standard did not have any material impact on revenues in the three months ended April 1, 2018. Prior period amounts were not adjusted and have continued to be reported in accordance with our historic accounting under Topic 605. While we considered an adjustment to opening retained earnings as prescribed by the modified retrospective method, there was no material adjustment ultimately required. Furthermore, there was no material difference between the prior period amounts as reported under ASC 605 and such amounts as would have been reported under ASC 606. Information about the nature, amount and timing of our revenues from contracts with customers is disclosed in Note 10. Revenues. Our accounting policy for revenue recognition is set forth below.

Revenue Recognition

Revenue from the sale of products is recognized when control of the promised goods is transferred to our customers based on the agreed-upon shipping terms, in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. Volume rebates, expected returns, discounts and other incentives to customers are considered variable consideration and we estimate these amounts based on the expected amount to be provided to customers and reduce the revenues we recognize accordingly. Sales taxes and value added taxes assessed by governmental entities are excluded from the measurement of consideration expected to be received. Shipping and handling costs incurred after a customer has taken possession of our goods are treated as a fulfillment cost and are not considered a separate performance obligation. Shipping and other transportation costs charged to customers are recorded in both revenues and cost of goods sold in the condensed consolidated statements of comprehensive income (loss).

Other Recent Accounting Pronouncements not yet Adopted

In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)", which will replace the existing guidance in ASC 840, "Leases." The updated standard aims to increase transparency and comparability among organizations by requiring lessees to recognize lease assets and lease liabilities on the balance sheet and requiring disclosure of key information about leasing arrangements. This ASU is effective for annual periods beginning after December 15, 2018, and interim periods within those annual periods; early adoption is permitted and modified retrospective application is required. While we are currently assessing the impact that ASU 2016-02 will have on our consolidated financial statements, we anticipate that the primary impact upon adoption will be to our consolidated balance sheets from the recognition, on a discounted basis, of our minimum commitments under non-cancelable operating leases, resulting in the recognition of right to use assets and lease obligations. Our current minimum undiscounted lease commitments under non-cancelable operating leases are disclosed in Note 9. Commitments and Contingencies.